Using a slow feedrate on a light cut allows the cutter to do its very best at removing all the material that it can. Thus, there is nothing left to be cut on a 'spring pass'. If you still recut when going over the same path twice, then your tool is not sharp enough, the amount to finish was excessive, or your feedrate was too high.
When attempting to interpolate a bore to roundness, use a sharp tool reserved for the finish cut. Use a seperate profiling operation (with tool radius compensation) to take the finish cut, rather than a machine cycle. Use the machine cycles to rough and semi-finish with, that is what they are for.
My suggestion is that you reserve maybe .002" for a finish cut. Tool deflection during heavier cuts will easily cause the 'overcut' effect in any areas where the tool traverses twice (as in your overlap zone).
Slow the feed down considerably when attempting to interpolate bores very accurately. I found I could get very good interpolated roundness on my Haas if interpolating at about 10 ipm (in aluminum)ie, approx .0002 variation.
First you get good, then you get fast. Then grouchiness sets in.
(Note: The opinions expressed in this post are my own and are not necessarily those of CNCzone and its management)